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An analysis of endocannabinoid concentrations and mood following singing and exercise in healthy volunteers.

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The euphoric feeling described after running is, at least in part, due to increased circulating endocannabinoids. Endocannabinoids are lipid signalling molecules involved in reward, appetite, mood, memory and neuroprotection. The aim of this study was to investigate whether activities other than running can increase circulating endocannabinoids. 9 healthy female volunteers (mean 61 yrs) were recruited from a local choir. Circulating endocannabinoids, haemodynamics, mood and hunger ratings were measured before and immediately after 30 min of dance, reading, singing or cycling in a fasted state. Singing increased plasma levels of anandamide (AEA) by 42% (P<0.05), palmitoylethanolamine (PEA) by 53% (P<0.01) and oleoylethanolamine (OEA) by 34% (P<0.05), and improved positive mood and emotions (P<0.01), without affecting hunger scores.Dancing did not affect endocannabinoid levels or hunger ratings, but decreased negative mood and emotions (P<0.01). Cycling increased OEA levels by 26% (P<0.05) and tended to decrease how hungry volunteers felt, without affecting mood. Reading increased OEA levels by 28% (P<0.01) and increased the desire to eat. Plasma AEA levels were positively correlated with how full participants felt (P<0.05).Plasma OEA levels were positively correlated with positive mood and emotions (P<0.01). All three ethanolamines were positively correlated with heart rate (P<0.0001). These data suggest that activities other than running can increase plasma endocannabinoids associated with changes in mood or appetite. Increases in endocannabinoids may underlie the rewarding and pleasurable effects of singing and exercise, and ultimately some of the long-term beneficial effects on mental health, cognition and memory.
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ORIGINAL RESEARCH
published: 26 November 2018
doi: 10.3389/fnbeh.2018.00269
An Analysis of Endocannabinoid
Concentrations and Mood Following
Singing and Exercise in Healthy
Volunteers
Nicole L. Stone1,Sophie A. Millar1,Philip J. J. Herrod1,David A. Barrett2,
Catharine A. Ortori2,Valerie A. Mellon3and Saoirse E. O’Sullivan1*
1Division of Medical Sciences and Graduate Entry Medicine, School of Medicine, University of Nottingham, Nottingham,
United Kingdom, 2Centre for Analytical Bioscience, Advanced Materials and Healthcare Division, School of Pharmacy,
University of Nottingham, Nottingham, United Kingdom, 3BBC Studios “Trust Me I’m a Doctor”, BBC Scotland, Glasgow,
United Kingdom
Edited by:
Walter Adriani,
Istituto Superiore di Sanità (ISS), Italy
Reviewed by:
Maria Morena,
University of Calgary, Canada
Antonia Manduca,
Aix-Marseille Université, France
*Correspondence:
Saoirse E. O’Sullivan
mbzso@nottingham.ac.uk
Received: 24 August 2018
Accepted: 22 October 2018
Published: 26 November 2018
Citation:
Stone NL, Millar SA, Herrod PJJ,
Barrett DA, Ortori CA, Mellon VA and
O’Sullivan SE (2018) An Analysis of
Endocannabinoid Concentrations
and Mood Following Singing and
Exercise in Healthy Volunteers.
Front. Behav. Neurosci. 12:269.
doi: 10.3389/fnbeh.2018.00269
The euphoric feeling described after running is, at least in part, due to increased
circulating endocannabinoids (eCBs). eCBs are lipid signaling molecules involved in
reward, appetite, mood, memory and neuroprotection. The aim of this study was
to investigate whether activities other than running can increase circulating eCBs.
Nine healthy female volunteers (mean 61 years) were recruited from a local choir.
Circulating eCBs, haemodynamics, mood and hunger ratings were measured before and
immediately after 30 min of dance, reading, singing or cycling in a fasted state. Singing
increased plasma levels of anandamide (AEA) by 42% (P<0.05), palmitoylethanolamine
(PEA) by 53% (P<0.01) and oleoylethanolamine (OEA) by 34% (P<0.05) and improved
positive mood and emotions (P<0.01), without affecting hunger scores. Dancing did
not affect eCB levels or hunger ratings, but decreased negative mood and emotions
(P<0.01). Cycling increased OEA levels by 26% (P<0.05) and tended to decrease
how hungry volunteers felt, without affecting mood. Reading increased OEA levels by
28% (P<0.01) and increased the desire to eat. Plasma AEA levels were positively
correlated with how full participants felt (P<0.05). Plasma OEA levels were positively
correlated with positive mood and emotions (P<0.01). All three ethanolamines were
positively correlated with heart rate (HR; P<0.0001). These data suggest that activities
other than running can increase plasma eCBs associated with changes in mood or
appetite. Increases in eCBs may underlie the rewarding and pleasurable effects of singing
and exercise and ultimately some of the long-term beneficial effects on mental health,
cognition and memory.
Keywords: endocannabinoids, anandamide, human, clinical, high, mood, singing and dancing
Abbreviations: 2-AG, 2-arachidonoylglycerol; AEA, anandamide; BBB, blood brain barrier; BDNF, brain derived neurotrophic
factor; eCBs, endocannabinoids; LC-ESI-MS-MS, electrospray ionization liquid chromatography/mass spectrometry; OEA,
oleoylethanolamine; PEA, palmitoylethanolamine.
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Stone et al. Endocannabinoids in Cycling, Dancing and Singing
INTRODUCTION
The classic ‘‘runners high’’ is described as the sense of well-being
and mood elevation associated with moderate distance running.
Other typical indicators include a decrease in anxious thinking
(anxiolytic), positive emotions/mood (euphoria), reduced pain
perception (analgesia) and a feeling of increased endurance
(Sparling et al., 2003; Dietrich and McDaniel, 2004; Tsatsoulis
and Fountoulakis, 2006; Raichlen et al., 2012). To explain
these positive effects post-exercise, attention was directed to
the endocannabinoid (eCB) system, and a number of groups
have found significant correlations between physical activity,
mood and elevated eCB levels. Interestingly, the majority of
studies have only observed significant rises in the first identified
eCB, anandamide (AEA; Sparling et al., 2003; Heyman et al.,
2012; Raichlen et al., 2013), whilst the reports analyzing
2-arachidonylglycerol (2-AG) levels post-exercise have been less
clear. Heyman et al. (2012) reported no change in circulating
2-AG levels after cycling. However, Brellenthin et al. (2017)
showed that 2-AG and AEA were significantly increased in
a study analyzing the effects of preferred (self-selected) and
prescribed (70%–75% of max) exercise on eCB levels and mood.
The eCB system consists of the cannabinoid receptors
1 and 2 (CB1and CB2), eCBs, and the enzymes that are
responsible for their synthesis and breakdown (Devane et al.,
1992; Mechoulam et al., 1995; De Petrocellis and Di Marzo,
2009). AEA and 2-AG are partial agonists of CB1and CB2,
whilst palmitoylethanolamine (PEA) and oleoylethanolamine
(OEA) share similar synthesis and degradation mechanisms,
without directly interacting with these receptors themselves
(Hansen et al., 2000; Okamoto et al., 2004). Instead, these
molecules interact with other receptors, primarily peroxisome
proliferator-activated receptor alpha (PPAR-α) and transient
receptor potential cation channel subfamily V member 1
(TRPV1; Ahern, 2003; Fu et al., 2003; Lo Verme et al., 2005a,b;
Karwad et al., 2017). eCB signaling mediates a number of
physiological and psychological processes including emotional
responses, cognition, memory, motor behavior, feeding and
energy consumption (Berger and Motl, 2000; Cota et al., 2003;
Cota, 2007; Brellenthin et al., 2017). Studies have also established
prominent roles of eCB signaling in the positive reinforcement
in reward driven activities such as masturbation, arousal, binge-
eating and social interactions in humans (Klein et al., 2012;
Monteleone et al., 2015, 2017; Fuss et al., 2017).
Singing and dancing, especially as a group activity, are
associated with positive mood in humans (Zajenkowski et al.,
2015; Pearce et al., 2016; Tarr et al., 2016; Schladt et al., 2017).
However, little has been studied to elucidate how these positive
emotions are mediated. Recently, Hahn et al. (2017) studied
the relationship between song practice and the eCB system in
European starlings. They found a significant positive correlation
between conditioned place preference (a measure of reward
and song production), the number of songs a bird produced
and the expression of CB1in areas of the brain associated
with reward, primarily the ventral tegmental area. Therefore
suggesting a role for eCB signaling in singing and reward (Hahn
et al., 2017; Riters et al., 2017). In humans, singing has been
studied as a therapy for long-term disorders such as Alzheimer’s
(to improve cognition, memory and long-term pain), chronic
obstructive pulmonary disease, as well as to improve mood in
conditions such as anxiety and depression (Reagon et al., 2016;
Kang et al., 2017). Similarly, dancing has been explored as a
potential therapy for cognitive and emotional dysfunction in
conditions such as depression, dementia and Parkinson’s. In a
systematic review of 11 studies, Kiepe et al. (2012) found that
depression and psychological distress were reduced by dance
therapy in patients suffering from Parkinson’s, diabetes, breast
cancer or heart failure. Dance therapy in a group of 60 students
also significantly reduced depression over a period of 12 weeks
(Akandere and Demir, 2011). To date, no study has assessed
singing or dancing and whether they modulate eCB levels in
humans and whether that correlates to an improved mood. Given
that mood is central in the measure of overall psychological well-
being, low intensity activities that can positively modulate mood
could be useful therapeutic tools in numerous conditions such
as depression, anxiety and stress, especially if a patient cannot
undertake moderate/higher intensity exercise.
The purpose of this study was to investigate whether activities
other than running can give you a measurable ‘‘high’’ through
changes in circulating eCBs levels. We examined activities that
are associated with euphoria (singing and dancing) as well as an
exercise regime other than running (cycling), with the hypothesis
that these activities would increase plasma eCB levels. Quiet
reading was used as a control condition. A secondary objective
of this study was to establish whether there was a link between
cycling, dancing, singing and reading with regards to mood and
hunger ratings.
MATERIALS AND METHODS
Participants
All procedures were approved by the University of Nottingham
Faculty of Health Sciences ethics committee, and were carried
out according to the declaration of Helsinki. Nine healthy
post-menopausal female volunteers (age range 55–67, mean
61 years) were recruited from a local choir as people who
enjoyed singing and exercise. The inclusion criteria were that
volunteers be non-smokers, in good physical health, accustomed
to singing in a group, and also enjoy exercise. Volunteers gave
written informed consent prior to participation. The medications
taken included antihypertensives (n= 2), antacids (n= 2),
antidepressants/anti-anxiety medication (n= 2), HRT (n= 1),
and an inhaler for asthma (n= 1).
Subjects arrived fasted (feeding affects plasma eCB levels;
Monteleone et al., 2012) with no consumption of caffeine and
this was verbally confirmed on arrival at the study facility.
Participants were also asked to refrain from any exercise prior
to attending the laboratory. Volunteers were unaware of the
activity they were to perform on a given day until all baseline
measurements were made to avoid any anticipatory effects.
Study Days
Subjects came to the test site on four occasions between
8 am and 10 am in loose fitting sportswear. Each day,
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Stone et al. Endocannabinoids in Cycling, Dancing and Singing
individuals were asked to complete two questionnaires before
and after completing the activity. A visual analog scale (VAS)
questionnaire was used to assess how hungry subjects were
feeling on a scale of 1–10, using the questions ‘‘how hungry
do you feel?’’, ‘‘how full are you?’’, ‘‘how much food could you
eat?’’ and ‘‘how strong is your desire to eat?’’. A positive and
negative affect schedule (PANAS) questionnaire was used to
assess subject’s mood before and after each activity using the
following scoring system: 1 = ‘‘very slightly or not at all,’’ 2 = ‘‘a
little,’’ 2 = ‘‘moderately,’’ 4 = ‘‘quite a bit’’ and 5 = ‘‘extremely;’’
Watson et al., 1988; Crawford and Henry, 2004). Positive affect
score was calculated by adding the positive emotional responses
and the negative affect score was calculated based on the addition
of the negative affect scores.
Blood pressure was measured by oscillometry with the
participant seated according to the British Hypertension Society
guidelines, and heart rate (HR) was taken prior to commencing
the activity and immediately after finishing the activity. Blood
pressure and HR measurements were taken as the average over
three (pre-activity) or 2 (post-activity) measurements. Blood
draws (approximately 5 mL) were taken before commencing
the activity and immediately after finishing the activity into
pre-chilled K2-EDTA (Ethylenediaminetetraacetic acid) tubes
and immediately placed on ice. After collection, blood was
centrifuged at 2,000 gfor 15 min at 4C, plasma was removed
and aliquoted, and immediately snap frozen in liquid nitrogen.
Samples were stored at 80C until subsequent analysis.
After the baseline measurements were made, volunteers were
informed of the activity they were to perform. On day 1,
volunteers did a supervised 30 min dance exercise class preceded
by a 5 min warm up, to upbeat music. On day 2, volunteers did
30 min of supervised quiet reading (of boiler and dishwasher
catalogs) to classical music. On day 3, volunteers for 30 min choir
practice led by their choral director. On day 4, volunteers did a
30 min spin class (cycling) with a qualified instructor from the
University of Nottingham Sports facility, with a 5 min warm up
to upbeat music. All activities were performed as a group.
eCB Quantification
eCB analysis was based on the method as described by
Richardson et al. (2007). Samples were thawed and 100 µL
of internal standard of 2-AG-d8 (10 µM) and 15 µL of
AEA-d8 (28 µM) were added to a 0.4 mL aliquot of each
plasma sample or blank sample (0.4 mL water) vortexed briefly.
Ethyl acetate:hexane (9:1 v/v) was added to each sample and
subjected for a slow vortex (10 min) and centrifuged for
13,000 rpm, 10 min, 4C. The supernatants were transferred
and the procedure was repeated. Supernatants were then
pooled and evaporated using a centrifugal evaporator.
Prior to analysis, each sample extract was reconstituted in
100 µL of acetonitrile (ACN). Standards for AEA, 2-AG, PEA,
OEA, N-(2-hydroxyethyl)-9Z-octadecenamide), arachidonyl
ethanolamide-d8 (N-(2-Hydroxyethyl)-5Z, 8Z, 11Z, 14Z-
eicosatetraenamide-d8, AEA-d8) and 2-arachidonyl glycerol-d8
(2-AG-d8, (5Z, 8Z, 11Z, 14Z)-5, 8, 11, 14-Eicosatetraenoic acid-
d8, 2-hydroxy-1-(hydroxymethyl)ethyl ester-d8) were purchased
from Cambridge BioSciences, UK.
Following sample preparation, 10 µL of final sample
extract was analyzed using liquid chromatography electrospray
ionisation mass spectrometry (LC-ESI-MS/MS). The HPLC
system used was a modular Shimadzu Vp series LC (Shimadzu,
Milton Keynes, UK), with pumps, chilled autosampler and
column oven. The HPLC column used was an ACE 3 C8
(100 ×2.1 mm, 3 mm) with guard column. The mobile phase A
was water with 1 g/L ammonium acetate and 0.1% formic acid
and mobile phase B was ACN with 1 g/L ammonium acetate
and 0.1% formic acid pre-dissolved in 10% H2O. The flow rate
was 300 µL/min. The MS system used was a SCIEX 4000 QTrap
triple quadrupole mass spectrometer (Sciex, Warrington, UK)
operated in electrospray positive multiple reaction monitoring
mode. Quantification was performed using Analyst 1.6 and
identification of each compound in plasma was confirmed by
LC retention times of each standard and precursor and product
ion m/z ratios. The peak area of each analyte is compared to a
known amount of standard to determine the amount of target
compound present.
2-AG in these samples were below the limit of quantification
with our methodology in the plasma samples and the data has not
been reported.
Statistical Analysis
Data is presented as a scatter plot with mean ±SEM. Data sets
were compared by paired Student’s t-test pre and post-activity.
Correlations between plasma eCBs levels and hunger ratings,
cardiovascular parameters or mood pre and post-activities were
analyzed by linear regression. A quality control check was
performed by a separate researcher on data entry.
RESULTS
All but one of the participants completed the study in full;
one participant was unable to finish the cycling activity and
did not have a final blood draw or complete the surveys. Thus
nine participates were in the final comparison, except for the
cycling activity where n= 8.
Haemodynamics
Thirty minutes of dancing significantly increased HR
(t(8)= 4.894, P<0.01, Figure 1A) and decreased diastolic
blood pressure (t(8)= 2.764, P<0.05, Figure 1I). Thirty
minutes of reading caused a small but significant reduction
in HR (t(8)= 3.736, P<0.01, Figure 1B). Thirty minutes of
singing increased systolic blood pressure (t(8)= 5.66, P<0.001,
Figure 1G). Thirty minutes of cycling significantly increased
HR (t(7)= 7.314, P<0.001, Figure 1D) and decreased diastolic
blood pressure (t(7)= 2.567, P<0.05, Figure 1L).
Hunger Scores
The only significant change in hunger and appetite scores were
observed after 30 min of reading when volunteers reported
a significantly higher desire to eat (Figure 2N). Volunteers
tended to have reduced hunger ratings after dancing, singing and
cycling (Figure 2), but this only reached near significance for
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Stone et al. Endocannabinoids in Cycling, Dancing and Singing
FIGURE 1 | Changes in cardiovascular parameters (heart rate, HR; A–D), systolic blood pressure (E–H) and diastolic blood pressure (I–L) before and after 30 min
activity (dancing, reading, singing or cycling) in nine healthy female volunteers. Data is presented as a scatter plot with mean ±SEM. Data sets were compared by
paired Student’s t-test pre and post-activity (P<0.05, ∗∗P<0.01 and ∗∗∗ P<0.001).
the question ‘‘how hungry do you feel?’’ immediate post-cycling
(t(7)= 2.348, P= 0.0512, Figure 2D).
Mood Scores
Dancing decreased negative mood and emotions (t(8)= 3.671,
P<0.01, Figure 3E), while reading decreased positive mood
and emotions (t(8)= 5.751, P<0.001, Figure 3B). Only singing
was found to significantly improve positive mood and emotions
(t(8)= 4.951, P<0.01, Figure 3C) and also tended to decrease
negative mood and emotions (eight out of nine volunteers
reported a lower NAS post-singing, Figure 3E). Cycling has no
effect on mood ratings.
Plasma Levels of Endocannabinoids
Dancing had no effect on circulating levels of eCBs measured
immediately the activity, although there was a trend for AEA and
OEA levels to be increased (Figures 4A,E). Thirty minutes of
reading significantly increased plasma OEA levels (t(8)= 4.586,
P<0.01, Figure 4F) and tended to increase PEA levels
(t(8)= 2.02, P= 0.078, Figure 4J). Singing significantly increased
the plasma levels of all eCBs measurable; AEA (t(8)= 3.049,
P<0.05, Figure 4C), OEA (t(8)= 4.81, P<0.01, Figure 4G)
and PEA (t(8)= 3.319, P<0.05, Figure 4K). OEA levels were also
increased after 30 min cycling (t(6)= 3.594, P<0.05, Figure 4H).
At baseline (before activities started) across all 4 days, there
was a significant positive correlation between plasma OEA levels
and the rating for ‘‘how much food could you eat?’’ (r2= 0.2226,
F= 9.16, P<0.01) and positive mood and emotions (r2= 0.1355,
F= 5.172, P<0.05). Resting HR was positively correlated with
both plasma AEA (r2= 0.3363, F= 16.72, P<0.001) and PEA
(r2= 0.169, F= 6.711, P<0.05) levels.
Across all days and time points (pre- and post-activity),
plasma AEA levels were positively correlated with the rating for
‘‘how full are you?’’ (r2= 0.0626, F= 4.472, P<0.05, Figure 5A),
and plasma OEA levels tended to be positively correlated with
the rating for ‘‘how much food could you eat?’’ (r2= 0.0404,
F= 2.821, P= 0.097, Figure 5B) and ‘‘how strong is your desire
to eat?’’ (r2= 0.04624, F= 3.248, P= 0.076, Figure 5C) and with
increased ratings for positive mood and emotion (r2= 0.1269,
F= 9.879, P<0.01, Figure 5D). All three ethanolamines were
positively correlated with HR (AEA: r2= 0.4394, F= 53.3,
P<0.0001, Figure 5E; OEA: r2= 0.2639, F= 24.37, P<0.0001,
Figure 5F and PEA: r2= 0.2093, F= 18, P<0.0001, Figure 5G).
DISCUSSION
It is well reported that running is correlated with mood elevation.
These positive effects have been attributed to an evolutionary
trait, where positive re-enforcement ultimately led to increased
food foraging, survival and subsequent passing of relevant genes
to offspring and have recently been attributed, at least in part,
to increases in eCBs (Bramble and Lieberman, 2004; Raichlen
et al., 2012). Our study aimed to examine whether activities other
than running also increase eCBs and enhance mood. We have
shown for the first time that singing significantly increases levels
of AEA, OEA and PEA in healthy post-menopausal females and
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Stone et al. Endocannabinoids in Cycling, Dancing and Singing
FIGURE 2 | Changes in hunger and appetite scores as assessed using a visual analog scale (VAS) (1–10) before and after 30 min activity (dancing (A,E,L,M),
reading (B,F,J,N), singing (C,G,K,O) or cycling (D,H,L,P) in nine healthy female volunteers. Data is presented as a scatter plot with mean ±SEM. Data sets were
compared by paired Student’s t-test pre and post-activity (P<0.05).
enhanced mood. Dancing (on mood) and cycling (on eCBs) also
had positive effects in this group. Although singing was the most
beneficial activity in this study, this is likely to reflect the fact
that the volunteers were recruited from local choirs and already
find this an enjoyable activity. These data provide biochemical
evidence of an increase in novel signaling messengers known
to improve mood, reduce stress and anxiety, enhance memory,
protect brain function and reduce pain.
Singing, in particular group singing, has been associated with
an increase in positive mood and improved immune function
in humans (Kreutz et al., 2004; Schladt et al., 2017). Choir
singing also enables social interactions, exhibiting a greater
benefit to mood than singing alone (Schladt et al., 2017). Our
results also demonstrate that singing increases mood, and also
for the first time that singing increasing circulating levels of
AEA, OEA and PEA. As AEA is a partial agonist of CB1
and has full agonist activity at TRPV1, an increase in the
levels of AEA post activity could therefore facilitate increases
in positive emotions, as well as anxiolytic and analgesic effects
(Chapman et al., 2009; Starowicz et al., 2012). Levels of OEA
post activity were correlated with a decrease in hunger and
desire to eat. This supports previous data that OEA attenuates
food consumption and increase lipolysis and energy expenditure
(Lo Verme et al., 2005a,b). In vivo studies conducted in mice
have also suggested beneficial neuroprotective effects of OEA,
this protective effect could potentially be translated to humans
and warrants further study (Galan-Rodriguez et al., 2009; Zhou
et al., 2012; Yang et al., 2015). An abundance of evidence
has supported PEA as a potential therapy for neurological
and inflammatory disorders, particularly those associated with
pain (Costa et al., 2008; Keppel Hesselink, 2012; Esposito
and Cuzzocrea, 2013). PEA has also been taken into clinical
trials, whereby 600 mg of PEA was shown to be effective
in various pain states, without exhibiting any safety issues
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Stone et al. Endocannabinoids in Cycling, Dancing and Singing
FIGURE 3 | Changes in postive (PAS, A–D) and negative (NAS, E–H) mood and emotions before and after 30 min activity (dancing, reading, singing or cycling) in
nine healthy female volunteers. Data is presented as a scatter plot with mean ±SEM. Data sets were compared by paired Student’s t-test pre and post-activity
(∗∗P<0.01, ∗∗∗ P<0.001).
FIGURE 4 | Plasma endocannabinoid levels (AEA, anandamide, A–D; OEA, oleoylethanolamine, E–H; PEA, palmitoylethanolamine, I–L) before and after 30 min
activity (dancing, reading, singing or cycling) in nine healthy female volunteers. Data is presented as a scatter plot with mean ±SEM. Data sets were compared by
paired Student’s t-test pre and post-activity (P<0.05, ∗∗P<0.01).
(Hesselink and Hekker, 2012). Therefore, it could be beneficial
to increase levels of PEA via activities such as singing, to
promote neuroprotection, analgesia and reduce inflammation.
It is also important to note that increasing OEA and PEA can
indirectly increase AEA responses by the entourage effect by
competitive inhibition of AEA degradation by fatty acid amide
hydrolase (FAAH; Di Marzo et al., 2001; Costa et al., 2008; Ho
et al., 2008). Overall, singing could be a valuable activity in
patient populations that suffer with dysfunctions in psychological
well-being and struggle to participate in aerobic/moderate
intensity exercise.
Cycling resulted in a significant increase in OEA, and in
a trend for increases in both AEA and PEA. These changes
corresponded with a decrease in participants desire to eat and
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Stone et al. Endocannabinoids in Cycling, Dancing and Singing
FIGURE 5 | Correlations between plasma eCBs levels and appetite (A–C), mood (D) and HR (E–G) in healthy female volunteers when measured pre or
post-activities and analyzed by linear regression.
how hungry they felt. These data are consistent with results from
a previous study where plasma OEA levels were significantly
increased after 30 min of cycling in 16 male non-smokers with
a mean age of 22.9 years (Cedernaes et al., 2016). Our data did
not show that cycling positively affected mood (no increase in
PAS or decrease in NAS). Brellenthin et al. (2017) showed that
acute aerobic exercise (both prescribed and preferred) resulted
in positive mood outcomes in individuals capable of a range
of levels of physical activity, as well as showing modulation of
the eCB system. Interestingly, the group that undertook their
‘‘preferred exercise’’ had the best effect in reducing anxiety and
improving mood. In the present study, singing by participants
recruited from a choir support these observations, suggesting
that the eCB system is not only responsible for the motivation
for exercise (i.e., reward driven), but also the pleasure associated
with an activity that an individual enjoys. It would also have
been interesting if another group had been included (i.e. not
recruited from a choir) to directly assess the concept of preferred
vs. prescribed activity and to confirm that carrying out an activity
that is ‘‘pleasurable’’ to an individual is an important factor in
the psychological benefits of exercise and other related activities.
Subjects were also not asked to rate how much they enjoyed each
of the activities, this would have been an interesting endpoint to
assess to what degree the participant’s moods were influenced
by how much they liked a particular activity and should be
considered in future study. These factors would also have
provided further evidence to why individuals in this study failed
to experience positive mood changes or significant increases in
AEA post cycling; compared with the study by Heyman et al.
(2012) where increases in AEA were seen in well-trained cyclists,
who presumably enjoy cycling.
Exercise intensity may be another factor explaining the lack
of AEA increases in our participants. Brellenthin et al. (2017)
showed that the greatest increases in 2-AG and AEA were seen
in the higher intensity exercise group. Sparling et al. (2003) also
showed significant increases in AEA when participants reached
70%–80% max HR. According to Gulati et al. (2010), maximum
HR for women is calculated as 206(0.88 ×age of patient). As
the average age of our participants was 61 years, their average
maximum HR (max HR) is approximately 154 bpm, meaning
their 70%–80% max HR should be 107–123 bpm. Cycling was
the only activity that almost reached this (average 102 bpm
immediately post exercise) and dancing resulted in an average
HR of 95 bpm (immediately post exercise). This could suggest
that our activities may not have been intense enough to elicit
significant changes in circulating eCBs.
A number of studies have shown that dance is an effective
therapy in improving mood (including mild depression),
enhancing social interactions, boosting self-confidence, as well
as improving physical activity (Akandere and Demir, 2011; Kiepe
et al., 2012; Meekums et al., 2015). In one study, dancing caused
an increase in plasma serotonin levels and a decrease in negative
psychological symptoms in a group of 20 female adolescents
with mild depression, compared to 20 control subjects (Jeong
et al., 2005). We found post activity that there was a significant
decrease in negative emotions following 30 min of dancing. It
should be acknowledged that the decrease in negative emotions
could also be because this was the activity undertaken on day 1
and participants had higher NAS scores before starting the study.
Although there was a trend in increasing levels of AEA and
OEA levels post-activity, this did not reach significance. Our
results suggest that dancing did not effectively increase eCB levels
or improve mood, however this could be because they were
unfamiliar with the class, therefore not finding it as enjoyable as
singing as this was more familiar to them, or that the class was not
at a high enough intensity to produce changes in eCB levels. It
should also be noted that our participants were older than those
previously studied, and there could be an age-related decline in
the eCB response to exercise.
Reading was used as a control activity to assess baseline
eCB levels and mood. We found that reading was the only
activity that increased participants desire to eat but had little
impact on overall fullness or actual hunger and was correlated
to increases in OEA post activity. Reading also decreased the
ratings for positive mood and emotions. In hindsight, because
subjects were unaware of the task, the activity set-up looked
Frontiers in Behavioral Neuroscience | www.frontiersin.org 7November 2018 | Volume 12 | Article 269
Stone et al. Endocannabinoids in Cycling, Dancing and Singing
like they were about to take an exam, which may have resulted
in unforeseen heightened anxiety levels. Recent studies have
implicated the eCB system as a possible mediator of hedonic
vs. homeostatic eating response to the consumption of food
(as a reward) as well as acute stress and anxiety (Matias et al.,
2006; Monteleone et al., 2015, 2017). Dlugos et al. (2012)
showed that AEA, PEA and OEA were all increased in serum
in response to stress. They also found that higher levels of
AEA at baseline, associated with decreased levels of anxiety.
Furthermore, a common phenomenon is that typically negative
emotions, particularly boredom, stress and depressive emotions
increase our desire to eat in order to increase positive emotions
(Koball et al., 2012; Yau and Potenza, 2013; Moynihan et al.,
2015). These factors could explain the elevated levels of OEA post
activity and lower PAS scores.
A limitation of our study is that participants already had
very low negative affect scores and high positive affect scores.
This suggests that the individuals that took part in the study
were generally happy and positive and there was therefore little
room for mood to be further improved. It would therefore be
interesting in future work to see the effects of these same activities
on individuals that exhibit depressive, or anxious behavior in
order to see greater differences in negative emotional responses.
Intensity of a physical activity has also been shown to influence
exercise induced increases in eCB levels. Raichlen et al. (2013)
built on previous work showing that eCBs follow a U-shaped
curve, with moderate level activity resulting in the biggest
increase in eCB levels (Berger and Motl, 2000). This trend in
eCB levels is also correlated with mood as the positive emotional
state post exercise is not experienced at very low or very high
intensities (Berger and Motl, 2000). As all the participants were
unfamiliar to the activities they carried out, a lot of their focus
would have been on ‘‘mastering’’ the class rather than actually
enjoying it in the moment.
It can also not be overlooked that this study only recruited
healthy female volunteers. Evidence from animal studies has
already shown distinct sexual dimorphism in the eCB system,
particularly in CB1expression and activation (Reich et al., 2009;
Mateos et al., 2011; Dias-Rocha et al., 2018). Limited preliminary
evidence from human studies have also shown variations in the
eCB system between males and females (Cupini et al., 2006; Hill
et al., 2008). Thus future study should look to establish whether
the effects observed in this study translate to male participants as
well as females.
In conclusion, we found that activities other than running
(singing, dancing and cycling) can increase plasma eCB levels.
Singing was the only activity to increase plasma levels of AEA
and improve positive mood outcomes, suggesting that singing
in this group of volunteers was able to produce an endogenous
‘‘high.’’ This is interesting as the participants were recruited
from a choir, suggesting that the enjoyment of an activity may
influence their feeling of reward and the eCB response. This
preliminary evidence suggests that activities like singing could
be recommended to individuals suffering from mood disorders
such as anxiety and depression, as well as a potential therapy
for neurological and inflammatory disorders. Future research
should consider an individual’s preference to a particular activity,
as this could be an important factor in influencing the eCB
system, as well as being a factor in deciding appropriate
therapy.
AUTHOR CONTRIBUTIONS
NS and SO’S wrote the article with contributions from all the
other authors. SO’S, SM and NS carried out cardiovascular
measurements, surveys and blood processing. SO’S processed the
study data and performed the statistical analysis. CO and DB
performed the eCB analysis on the plasma samples. PH carried
out the blood draws from the subjects. VM developed the study
with SO’S.
FUNDING
The eCB analysis was funded by BBC Studios. This work was
supported by the Biotechnology and Biological Sciences Research
Council (grant number BB/M008770/1).
ACKNOWLEDGMENTS
We would like to thank the participants for taking part in this
study, and the BBC Studios ‘‘Trust Me I’m a Doctor’’ team for all
their help in the organization of the study. We would also like to
thank the singing, dance and cycling instructors who supervised
the activities for their time and help.
REFERENCES
Ahern, G. P. (2003). Activation of TRPV1 by the satiety factor oleoylethanolamide.
J. Biol. Chem. 278, 30429–30434. doi: 10.1074/jbc.M305051200
Akandere, M., and Demir, B. (2011). The effect of dance over depression. Coll.
Antropol. 35, 651–656.
Berger, B. G., and Motl, R. W. (2000). Exercise and mood: a selective review
and synthesis of research employing the profile of mood states. J. Appl. Sport
Psychol. 12, 69–92. doi: 10.1080/10413200008404214
Bramble, D. M., and Lieberman, D. E. (2004). Endurance running and
the evolution of Homo. Nature 432, 345–352. doi: 10.1038/nature
03052
Brellenthin, A. G., Crombie, K. M., Hillard, C. J., and Koltyn, K. F. (2017).
Endocannabinoid and mood responses to exercise in adults with varying
activity levels. Med. Sci. Sports Exerc. 49, 1688–1696. doi: 10.1249/MSS.
0000000000001276
Cedernaes, J., Fanelli, F., Fazzini, A., Pagotto, U., Broman, J.-E., Vogel, H.,
et al. (2016). Sleep restriction alters plasma endocannabinoids concentrations
before but not after exercise in humans. Psychoneuroendocrinology 74, 258–268.
doi: 10.1016/j.psyneuen.2016.09.014
Chapman, V., Kendall, D., and Sagar, D. R. (2009). ‘‘Cannabinoid receptor
mediated analgesia: novel targets for chronic pain states,’’ in Synaptic
Plasticity in Pain, ed. M. Malcangio (New York, NY: Springer),
337–351.
Costa, B., Comelli, F., Bettoni, I., Colleoni, M., and Giagnoni, G. (2008). The
endogenous fatty acid amide, palmitoylethanolamide, has anti-allodynic and
anti-hyperalgesic effects in a murine model of neuropathic pain: involvement
of CB1, TRPV1 and PPARγreceptors and neurotrophic factors. Pain 139,
541–550. doi: 10.1016/j.pain.2008.06.003
Cota, D. (2007). CB1 receptors: emerging evidence for central and peripheral
mechanisms that regulate energy balance, metabolism, and cardiovascular
health. Diabetes Metab. Res. Rev. 23, 507–517. doi: 10.1002/dmrr.764
Frontiers in Behavioral Neuroscience | www.frontiersin.org 8November 2018 | Volume 12 | Article 269
Stone et al. Endocannabinoids in Cycling, Dancing and Singing
Cota, D., Marsicano, G., Tschöp, M., Grübler, Y., Flachskamm, C., Schubert, M.,
et al. (2003). The endogenous cennabinoid system affects energy balance via
central orexigenic drive and peripheral lipogenesis. J. Clin. Invest. 112, 423–431.
doi: 10.1172/jci200317725
Crawford, J. R., and Henry, J. D. (2004). The positive and negative affect
schedule (PANAS): construct validity, measurement propertiesand normative
data in a large non-clinical sample. Br. J. Clin. Psychol. 43, 245–265.
doi: 10.1348/0144665031752934
Cupini, L. M., Bari, M., Battista, N., Argirò, G., Finazzi-Agrò, A., Calabresi, P.,
et al. (2006). Biochemical changes in endocannabinoid system are expressed
in platelets of female but not male migraineurs. Cephalalgia 26, 277–281.
doi: 10.1111/j.1468-2982.2005.01031.x
De Petrocellis, L., and Di Marzo, V. (2009). An introduction to the
endocannabinoid system: from the early to the latest concepts. Best Pract. Res.
Clin. Endocrinol. Metab. 23, 1–15. doi: 10.1016/j.beem.2008.10.013
Devane, W. A., Hanus, L., Breuer, A., Pertwee, R. G., Stevenson, L. A., Griffin, G.,
et al. (1992). Isolation and structure of a brain constituent that binds to the
cannabinoid receptor. Science 258, 1946–1949. doi: 10.1126/science.1470919
Di Marzo, V., Melck, D., Orlando, P., Bisogno, T., Zagoory, O., Bifulco, M.,
et al. (2001). Palmitoylethanolamide inhibits the expression of fatty acid amide
hydrolase and enhances the anti-proliferative effect of anandamide in human
breast cancer cells. Biochem. J. 358, 249–255. doi: 10.1042/0264-6021:3580249
Dias-Rocha, C. P., Almeida, M. M., Santana, E. M., Costa, J. C. B., Franco, J. G.,
Pazos-Moura, C. C., et al. (2018). Maternal high-fat diet induces sex-specific
endocannabinoid system changes in newborn rats and programs adiposity,
energy expenditure and food preference in adulthood. J. Nutr. Biochem. 51,
56–68. doi: 10.1016/j.jnutbio.2017.09.019
Dietrich, A., and McDaniel, W. F. (2004). Endocannabinoids and exercise. Br.
J. Sports Med. 38, 536–541. doi: 10.1136/bjsm.2004.011718
Dlugos, A., Childs, E., Stuhr, K. L., Hillard, C. J., and de Wit, H. (2012). Acute stress
increases circulating anandamide and other N-acylethanolamines in healthy
humans. Neuropsychopharmacology 37, 2416–2427. doi: 10.1038/npp.2012.100
Esposito, E., and Cuzzocrea, S. (2013). Palmitoylethanolamide in homeostatic and
traumatic central nervous system injuries. CNS Neurol. Disord. Drug Targets
12, 55–61. doi: 10.2174/1871527311312010010
Fu, J., Gaetani, S., Oveisi, F., Lo Verme, J., Serrano, A., Rodríguez De
Fonseca, F., et al. (2003). Oleylethanolamide regulates feeding and body
weight through activation of the nuclear receptor PPAR-α.Nature 425, 90–93.
doi: 10.1038/nature01921
Fuss, J., Bindila, L., Wiedemann, K., Auer, M. K., Briken, P., and Biedermann, S. V.
(2017). Masturbation to orgasm stimulates the release of the endocannabinoid
2-arachidonoylglycerol in humans. J. Sex. Med. 14, 1372–1379. doi: 10.1016/j.
jsxm.2017.09.016
Galan-Rodriguez, B., Suarez, J., Gonzalez-Aparicio, R., Bermudez-Silva, F. J.,
Maldonado, R., Robledo, P., et al. (2009). Oleoylethanolamide exerts partial
and dose-dependent neuroprotection of substantia nigra dopamine neurons.
Neuropharmacology 56, 653–664. doi: 10.1016/j.neuropharm.2008.11.006
Gulati, M., Shaw, L. J., Thisted, R. A., Black, H. R., Bairey Merz, C. N., and
Arnsdorf, M. F. (2010). Heart rate response to exercise stress testing in
asymptomatic women: the St. James women take heart project. Circulation 122,
130–137. doi: 10.1161/CIRCULATIONAHA.110.939249
Hahn, A. H., Merullo, D. P., Spool, J. A., Angyal, C. S., Stevenson, S. A., and
Riters, L. V. (2017). Song-associated reward correlates with endocannabinoid-
related gene expression in male European starlings (Sturnus vulgaris).
Neuroscience 346, 255–266. doi: 10.1016/j.neuroscience.2017.01.028
Hansen, H. S., Moesgaard, B., Hansen, H. H., Petersen, G. (2000).
N-Acylethanolamines and precursor phospholipids—relation to cell injury.
Chem. Phys. Lipids 108, 135–150. doi: 10.1016/s0009-3084(00)00192-4
Hesselink, J. M., and Hekker, T. A. (2012). Therapeutic utility of
palmitoylethanolamide in the treatment of neuropathic pain associated
with various pathological conditions: a case series. J. Pain Res. 5, 437–442.
doi: 10.2147/jpr.s32143
Heyman, E., Gamelin, F. X., Goekint, M., Piscitelli, F., Roelands, B., Leclair, E.,
et al. (2012). Intense exercise increases circulating endocannabinoid and
BDNF levels in humans—possible implications for reward and depression.
Psychoneuroendocrinology 37, 844–851. doi: 10.1016/j.psyneuen.2011.09.017
Hill, M. N., Miller, G. E., Ho, W. S., Gorzalka, B. B., and Hillard, C. J. (2008).
Serum endocannabinoid content is altered in females with depressive disorders:
a preliminary report. Pharmacopsychiatry 41, 48–53. doi: 10.1055/s-2007-
993211
Ho, W.-SV., Barrett, D. A., and Randall, M. D. (2008). ‘Entourage’ effects
of N-palmitoylethanolamide and N-oleoylethanolamide on vasorelaxation to
anandamide occur through TRPV1 receptors. Br. J. Pharmacol. 155, 837–846.
doi: 10.1038/bjp.2008.324
Jeong, Y.-J., Hong, S.-C., Lee, M. S., Park, M.-C., Kim, Y.-K., and Suh, C.-
M. (2005). Dance movement therapy improves emotional responses
and modulates neurohormones in adolescents with mild depression. Int.
J. Neurosci. 115, 1711–1720. doi: 10.1080/00207450590958574
Kang, J., Scholp, A., and Jiang, J. J. (2017). A review of the physiological effects
and mechanisms of singing. J. Voice 32, 390–395. doi: 10.1016/j.jvoice.2017.
07.008
Karwad, M. A., Macpherson, T., Wang, B., Theophilidou, E., Sarmad, S.,
Barrett, D. A., et al. (2017). Oleoylethanolamine and palmitoylethanolamine
modulate intestinal permeability in vitro via TRPV1 and PPARα.FASEB J. 31,
469–481. doi: 10.1096/fj.201500132
Keppel Hesselink, J. M. (2012). New targets in pain, non-neuronal
cells, and the role of palmitoylethanolamide. Open Pain J. 5, 12–23.
doi: 10.2174/1876386301205010012
Kiepe, M. S., Stöckigt, B., and Keil, T. (2012). Effects of dance therapy and ballroom
dances on physical and mental illnesses: a systematic review. Arts Psychother.
39, 404–411. doi: 10.1016/j.aip.2012.06.001
Klein, C., Hill, M. N., Chang, S. C., Hillard, C. J., and Gorzalka, B. B. (2012).
Circulating endocannabinoid concentrations and sexual arousal in women.
J. Sex. Med. 9, 1588–1601. doi: 10.1111/j.1743-6109.2012.02708.x
Koball, A. M. Meers, M. R., Storfer-Isser, A., Domoff, S. E., and Musher-
Eizenman, D. R. (2012). Eating when bored: revision of the emotional eating
scale with a focus on boredom. Health Psychol. 31, 521–524. doi: 10.1037/a00
25893
Kreutz, G., Bongard, S., Rohrmann, S., Hodapp, V., and Grebe, D. (2004).
Effects of choir singing or listening on secretory immunoglobulin A, cortisol,
and emotional state. J. Behav. Med. 27, 623–635. doi: 10.1007/s10865-00
4-0006-9
Lo Verme, J., Fu, J., Astarita, G., La Rana, G., Russo, R., Calignano, A., et al.
(2005a). The nuclear receptor peroxisome proliferator-activated receptor-
αmediates the anti-inflammatory actions of palmitoylethanolamide. Mol.
Pharmacol. 67, 15–19. doi: 10.1124/mol.104.006353
Lo Verme, J., Gaetani, S., Fu, J., Oveisi, F., Burton, K., and Piomelli, D. (2005b).
Regulation of food intake by oleoylethanolamide. Cell. Mol. Life Sci. 62,
708–716. doi: 10.1007/s00018-004-4494-0
Mateos, B., Borcel, E., Loriga, R., Luesu, W., Bini, V., Llorente, R., et al.
(2011). Adolescent exposure to nicotine and/or the cannabinoid agonist
CP 55,940 induces gender-dependent long-lasting memory impairments and
changes in brain nicotinic and CB1cannabinoid receptors. J. Psychopharmacol.
25, 1676–1690. doi: 10.1177/0269881110370503
Matias, I., Gonthier, M.-P., Orlando, P., Martiadis, V., De Petrocellis, L.,
Cervino, C., et al. (2006). Regulation, function, and dysregulation of
endocannabinoids in models of adipose and β-pancreatic cells and in obesity
and hyperglycemia. J. Clin. Endocrinol. Metab. 91, 3171–3180. doi: 10.1210/jc.
2005-2679
Mechoulam, R., Ben-Shabat, S., Hanus, L., Ligumsky, M., Kaminski, N. E.,
Schatz, A. R., et al. (1995). Identification of an endogenous 2-monoglyceride,
present in canine gut, that binds to cannabinoid receptors. Biochem. Pharmacol.
50, 83–90. doi: 10.1016/0006-2952(95)00109-d
Meekums, B., Karkou, V., and Nelson, E. A. (2015). Dance movement therapy for
depression. Cochrane Database Syst. Rev. 2:CD009895. doi: 10.1002/14651858.
CD009895
Monteleone, A. M., Di Marzo, V., Aveta, T., Piscitelli, F., Dalle Grave, R.,
Scognamiglio, P., et al. (2015). Deranged endocannabinoid responses to
hedonic eating in underweight and recently weight-restored patients with
anorexia nervosa. Am. J. Clin. Nutr. 101, 262–269. doi: 10.3945/ajcn.114.096164
Monteleone, A. M., Piscitelli, F., Dalle Grave, R., El Ghoch, M., Di Marzo, V.,
Maj, M., et al. (2017). Peripheral endocannabinoid responses to hedonic
eating in binge-eating disorder. Nutrients 9:E1377. doi: 10.3390/nu91
21377
Monteleone, P., Piscitelli, F., Scognamiglio, P., Monteleone, A. M., Canestrelli, B.,
Di Marzo, V., et al. (2012). Hedonic eating is associated with increased
Frontiers in Behavioral Neuroscience | www.frontiersin.org 9November 2018 | Volume 12 | Article 269
Stone et al. Endocannabinoids in Cycling, Dancing and Singing
peripheral levels of ghrelin and the endocannabinoid 2-arachidonoyl-glycerol
in healthy humans: a pilot study. J. Clin. Endocrinol. Metab. 97, E917–E924.
doi: 10.1210/jc.2011-3018
Moynihan, A. B., van Tilburg, W. A. P., Igou, E. R., Wisman, A., Donnelly, A. E.,
and Mulcaire, J. B. (2015). Eaten up by boredom: consuming food to escape
awareness of the bored self. Front. Psychol. 6:369. doi: 10.3389/fpsyg.2015.
00369
Okamoto, Y., Morishita, J., Tsuboi, K., Tonai, T., and Ueda, N. (2004).
Molecular characterization of a phospholipase D generating anandamide
and its congeners. J. Biol. Chem. 279, 5298–5305. doi: 10.1074/jbc.m3066
42200
Pearce, E., Launay, J., Machin, A., and Dunbar, R. I. (2016). Is group
singing special? Health, well-being and social bonds in community-based
adult education classes. J. Community Appl. Soc. Psychol. 26, 518–533.
doi: 10.1002/casp.2278
Raichlen, D. A., Foster, A. D., Gerdeman, G. L., Seillier, A., and Giuffrida, A.
(2012). Wired to run: exercise-induced endocannabinoid signaling in humans
and cursorial mammals with implications for the ‘runner’s high’. J. Exp. Biol.
215, 1331–1336. doi: 10.1242/jeb.063677
Raichlen, D. A., Foster, A. D., Seillier, A., Giuffrida, A., and Gerdeman, G. L.
(2013). Exercise-induced endocannabinoid signaling is modulated by intensity.
Eur. J. Appl. Physiol. 113, 869–875. doi: 10.1007/s00421-012-2495-5
Reagon, C., Gale, N., Enright, S., Mann, M., and van Deursen, R. (2016). A mixed-
method systematic review to investigate the effect of group singing on health
related quality of life. Complement. Ther. Med. 27, 1–11. doi: 10.1016/j.ctim.
2016.03.017
Reich, C. G., Taylor, M. E., and McCarthy, M. M. (2009). Differential effects of
chronic unpredictable stress on hippocampal CB1 receptors in male and female
rats. Behav. Brain Res. 203, 264–269. doi: 10.1016/j.bbr.2009.05.013
Richardson, D., Ortori, C. A., Chapman, V., Kendall, D. A., and Barrett, D. A.
(2007). Quantitative profiling of endocannabinoids and related compounds
in rat brain using liquid chromatography-tandem electrospray ionization
mass spectrometry. Anal. Biochem. 360, 216–226. doi: 10.1016/j.ab.2006.
10.039
Riters, L. V., Spool, J. A., Merullo, D. P., and Hahn, A. H. (2017). Song practice as
a rewarding form of play in songbirds. Behav. Processes doi: 10.1016/j.beproc.
2017.10.002 [Epub ahead of print].
Schladt, T. M., Nordmann, G. C., Emilius, R., Kudielka, B. M., de Jong, T. R.,
and Neumann, I. D. (2017). Choir versus solo singing: effects on mood, and
salivary oxytocin and cortisol concentrations. Front. Hum. Neurosci. 11:430.
doi: 10.3389/fnhum.2017.00430
Sparling, P. B., Giuffrida, A., Piomelli, D., Rosskopf, L., and Dietrich, A. (2003).
Exercise activates the endocannabinoid system. Neuroreport 14, 2209–2211.
doi: 10.1097/00001756-200312020-00015
Starowicz, K., Makuch, W., Osikowicz, M., Piscitelli, F., Petrosino, S., Di Marzo, V.,
et al. (2012). Spinal anandamide produces analgesia in neuropathic rats:
possible CB1- and TRPV1-mediated mechanisms. Neuropharmacology 62,
1746–1755. doi: 10.1016/j.neuropharm.2011.11.021
Tarr, B., Launay, J., and Dunbar, R. I. M. (2016). Silent disco: dancing in synchrony
leads to elevated pain thresholds and social closeness. Evol. Hum. Behav. 37,
343–349. doi: 10.1016/j.evolhumbehav.2016.02.004
Tsatsoulis, A., and Fountoulakis, S. (2006). The protective role of exercise on stress
system dysregulation and comorbidities. Ann. N Y Acad. Sci. 1083, 196–213.
doi: 10.1196/annals.1367.020
Watson, D., Clark, L. A., and Tellegen, A. (1988). Development and validation of
brief measures of positive and negative affect: the PANAS scales. J. Pers. Soc.
Psychol. 54, 1063–1070. doi: 10.1037/0022-3514.54.6.1063
Yang, L.-C., Guo, H., Zhou, H., Suo, D.-Q., Li, W.-J., Zhou, Y., et al. (2015).
Chronic oleoylethanolamide treatment improves spatial cognitive deficits
through enhancing hippocampal neurogenesis after transient focal cerebral
ischemia. Biochem. Pharmacol. 94, 270–281. doi: 10.1016/j.bcp.2015.02.012
Yau, Y. H., and Potenza, M. N. (2013). Stress and eating behaviors. Minerva
Endocrinol. 38, 255–267.
Zajenkowski, M., Jankowski, K. S., and Koata, D. (2015). Let’s dance—feel better!
Mood changes following dancing in different situations. Eur. J. Sport Sci. 15,
640–646. doi: 10.1080/17461391.2014.969324
Zhou, Y., Yang, L., Ma, A., Zhang, X., Li, W., Yang, W., et al. (2012).
Orally administered oleoylethanolamide protects mice from focal cerebral
ischemic injury by activating peroxisome proliferator-activated receptor α.
Neuropharmacology 63, 242–249. doi: 10.1016/j.neuropharm.2012.03.008
Conflict of Interest Statement: The authors declare that the research was
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be construed as a potential conflict of interest.
Copyright © 2018 Stone, Millar, Herrod, Barrett, Ortori, Mellon and O’Sullivan.
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Frontiers in Behavioral Neuroscience | www.frontiersin.org 10 November 2018 | Volume 12 | Article 269
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